*sigh* We do not know how skilled an Elder is. Plain and simple.
The Elders are individuals which have been selected to be the respected leaders of the yautja society. Or, if not the entire society, then the religious segment, as this is the portion which is responsible for the sacred hunts which occur in the films.
However, we do not know how strong they are, nor how weak. We do not know if they are revered because of physical strength, intellect, or the wisdom which comes with old age. For all we know, they could even be selected because of their bloodline.
Daveberg's statement appears to be based on the material from video games and possibly books since we have never seen an Elder do anything in the films but walk out of a ship, do some extremely minor action, then walk back on. For the record, video games and books are not canon material.
Based on the canon information which I have witnessed, I believe that the Elders are in fact the veterans of the yautja society which have become too old to engage in combat. Do you all honestly think that the yautja society would be inefficient enough to discard those whom have become unable to fight?
We do know that the Aztecs nominated their leaders based on their former skill on the battlefield and their ability to speak eloquently. If they yautja imprinted the Aztec culture onto the humans (as witnessed in AvP), then they would select their leaders in a similiar manner.
It makes more sense for the Elders to be old in age and wise than young and physicallly fit. If a yautja is old and still physically fit, then he or she would not become an elder because of the simple fact that he or she is still combat capable. He or she may become a candidate in the future, but for the time being that yautja would be kept out on the field so that it could continue to perform the traditions and rituals which surround their society and they appear to thoroughly enjoy.
Therefore, I believe that the Elders are, in fact, physically weaker than the other yautja, but they are much more intelligent and wise. Their intelligence and wisdom has allowed them to steer their people and their society from destruction for many milennia -- something a younger and more brash set of yautjas could not do.
And thus I clothe my naked villainy
With old odd ends stolen forth from holy writ
And seem a saint when most I play the devil.